> The resulting 500 response from the UAS does in fact > contain a Retry-After header. However, the condition > for sending this 500 response that does not match our > call flow states, "the UAS has received an offer to > which it has not yet generated an answer". In our > call-flow, the UAS has indeed answered the previous > offer via 183 w/ SDP, which leads me to believe the > 500 response is not appropriate for this call-flow.
>From an offer/answer perspective, the answer must be sent reliably. If offer sent within INVITE, an SDP within 18x response is not an "answer" SDP unless sent reliably by using 100rel per RFC 3262. RFC 3261 section 13.2.1: "If the initial offer is in an INVITE, the answer MUST be in a reliable non-failure message from UAS back to UAC which is correlated to that INVITE. For this specification, that is only the final 2xx response to that INVITE." RFC 3262 section 5: "RFC 3261 describes guidelines for the sets of messages in which offers and answers [3] can appear. Based on those guidelines, this extension provides additional opportunities for offer/answer exchanges. If the INVITE contained an offer, the UAS MAY generate an answer in a reliable provisional response (assuming these are supported by the UAC)." -- This email is intended solely for the person or entity to which it is addressed and may contain confidential and/or privileged information. If you are not the intended recipient and have received this email in error, please notify BroadSoft, Inc. immediately by replying to this message, and destroy all copies of this message, along with any attachment, prior to reading, distributing or copying it. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
